Lincoln Na5 Service Manual

							F-78TROUBLESHOOTING & REPAIRF-78
PROCEDURE
1.  Remove input power to the NA-5.
2.  With the 5/16 nutdriver locate andremove the four screws holding the
tach cover to the wire feed drive
motor.  See Figure F.13 
3.  Using the 5/16 nutdriver remove the two screws from the connection box
cover.
4.  Locate and disconnect the in-line connectors from leads #510A,
#525A and #555. 5.  Using the phillips head screwdriver,
remove the two screws from the
pick-up assembly cover .  See
Figure F.14.  Remove the cover.
6.  Hold the nut in place with the 3/8 wrench.  With the phillips head
screwdriver, remove the locking
screw from the rotating disc.  See
Figure F.15
TACH PC BOARD REMOVAL AND REPLACEMENT (Continued)
NA-5
FIGURE F.13 DRIVE MOTOR, TACH COVER, AND CONNECTION BOX
WIRE
DRIVE
MOTOR
MOUNTING
SCREWS (x4)
TACH COVER
PICKUP
ASSEMBLY
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							F-79TROUBLESHOOTING & REPAIRF-79
7.  Carefully remove the rotating discand tach PC board together.  Note
spacer washers underneath the disc.
8.  If tach PC board is to be removed carefully remove leads from connec-
tion box and cover plate.
TACH PC BOARD REMOVAL AND REPLACEMENT (Continued)
NA-5
FIGURE F.14 PICK-UP ASSEMBLY AND COVER
TACH ASSEMBLY
COVER
SCREWS
FIGURE F.15 ROTATING DISC, NUT AND TACH BOARD
DISC NUT
TACH
PC BOARD PHILLIPS
SCREW
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							F-80TROUBLESHOOTING & REPAIRF-80
REASSEMBLY
1.  Upon reassembly the spacers mustbe used to assure that the disc
rotates freely and smoothly within
the sensor window on the printed
circuit board.  Note the tach PC
board must be held in place when
aligning the rotating disc in the sen-
sor window.  Press down on the tach
PC board with your finger to simulate
the cover. 
2.  Use the 3/8 wrench to hold the nut in place.  Attach the rotating disc
with the phillips head screw.
3.  Thread leads #510A, #525A and #555 through the cover plate and
into the connection box. Attach to
their respective in-line connectors.
4.  Replace the connection box cover. 
5.  Replace the pick-up assembly cover.
6.  Reattach the tach cover to the wire feed drive motor.
TACH PC BOARD REMOVAL AND REPLACEMENT (Continued)
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							F-81TROUBLESHOOTING & REPAIRF-81
NA-5
WIRE DRIVE MOTOR REMOVAL AND REPLACEMENT
DESCRIPTION
This procedure will aid the technician in the removal and replacement of\
 the drive motor to
the gear box and also associated wiring to the control box.
MATERIALS NEEDED
7/16 Wrench
5/16 Nutdriver 
Large slot head screwdriver
Service and repair should be performed only by Lincoln Electric factory trained per-
sonnel. Unauthorized repairs performed on this equipment could result in danger to
the technician or the machine operator and will invalidate your factory warranty. For
your safety and to avoid electrical shock, please observe all safety notes and precau-
tions detailed throughout this manual.
If for any reason you do not understand the test procedures or are unable to perform
the tests/repairs safely, contact the Lincoln Electric service department for technical
troubleshooting assistance before you proceed.
Call (216) 383-2531 or (800) 833-9353 (WELD).
_____________________________________________________________
WARNING
This procedure takes approximately 35 minutes to perform.
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							F-82TROUBLESHOOTING & REPAIRF-82
MOTOR REMOVAL 
PROCEDURE
1.  Remove input power to the NA-5.
2.  Remove the motor and tach cablefrom the NA-5 control box.
3.  Perform  the 
Tach Board Removal
Procedure
.
4.  Using the slot head screwdriver remove the two screws mounting the
tach housing to the drive motor.
Remove the tach housing from the
drive motor.
5.  Using the phillips head screwdriver remove the cover plate adaptor.
See Figure F.16 6.  Using the 5/16 nutdriver remove the
clamp holding the connection box to
the drive motor.
7.  Carefully remove the connection box being careful not to stretch the leads.
WIRE DRIVE MOTOR REMOVAL AND REPLACEMENT (Continued)
NA-5
FIGURE F.16 DRIVE MOTOR AND TACH HOUSING
WIRE
DRIVE
MOTOR
TACH HOUSINGCOVER PLATE
 ADAPTER
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							F-83TROUBLESHOOTING & REPAIRF-83
8.  Remove leads #67, #627, #626,#539 and #541 from the terminal
strip in the connector box.
9.  Using the 7/16 wrench, remove two 1/4-20 bolts holding the adapter
plate and motor assembly to the wire
feed gear box.  (Older models may
have slot head 1/4-20 bolts).  See
Figure F.17
10. Using the large slot head screwdriv- er, remove the two slot head screws
that go through the wire feed gear
box and into the adapter plate.  11. Carefully remove the adapter plate
and motor assembly (with pinion
attached).
12.   With a slot head screwdriver,
remove  the adapter plate from the
drive motor.
WIRE DRIVE MOTOR REMOVAL AND REPLACEMENT (Continued)
NA-5
FIGURE F.17 DRIVE MOTOR
HEX HEAD
BOLT
ADAPTER 
PLATE AND 
 MOTOR
ASSEMBLY
WIRE DRIVE
 GEARBOX
SLOT  HEAD
 SCREW
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							F-84TROUBLESHOOTING & REPAIRF-84
MOTOR REPLACEMENT 
PROCEDURE
1.  Attach the adapter plate to the drivemotor using the slot head screwdriv-
er.
2.  Carefully install the replacement motor (with correct pinion) and
mount the adapter mounting plate
using the 1/4-20 bolts and slot head
screws previously removed.
3.  Attach leads #67, #627, #626, #539 and #541 to their respective termi-
nals in the connector box.  
4.  Carefully position the connector box and clamp to the drive motor and
using the 5/16 nutdriver secure in
position.  Be sure NOT to pinch
any  leads.
5.  Using the phillips head screwdriver mount the cover plate adaptor to the
drive motor.
6.  Using the slot head screwdriver attach the tach housing to the drive
motor.
7.  Perform  the 
Tach Board
Replacement Procedure
.
8.  Assemble the motor and tach cables to the NA-5 control box.
WIRE DRIVE MOTOR REMOVAL AND REPLACEMENT (Continued)
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							F-85TROUBLESHOOTING & REPAIRF-85
If a failed test indicates that any mechanical part that could affect th\
e machines electrical characteristics must be
replaced or if any electrical components are repaired or replaced, the m\
achine must be retested and must meet
the following standards.
Wire Feed Speed per following table:..........................
RETEST AFTER REPAIR
NA-5
LEDS  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Must operate per PC Board LED Definitions table in
Troubleshooting Section. 
Flux or Water Solenoid  . . . . . . . . . . . . . . . . . . . .Must operate when Start switch\
 is pressed.
Relay 3CR  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Must operate\
 and close power source contactor.
Relay 2CR  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Must operate\
 and activate external travel circuit, if used.
Voltmeter  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Refer to 
Voltmeter Accuracy Test.
Wire Speed Meter  . . . . . . . . . . . . . . . . . . . . . . . .Refer to 
Wire Speed Accuracy Test.
Voltage control and shutdown  . . . . . . . . . . . . . . .Refer to 
Out of Voltage Range Shut Down Test.
Gear  Ratio
Wire Speed Range in/min (m/min)
21/1 100-2070 (2.54-52.58)
57/1 38-778 (.97-19.76)
95/122-456 (.56-11.58)
142/1 15-300 (.38-7.62)
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							F-86NOTES   
NA-5
F-86
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							G-1ELECTRICAL DIAGRAMSG-1
TABLE OF CONTENTS 
-ELECTRICAL DIAGRAMS SECTION-
Electrical Diagrams ........................................................................\
............................................Section G Wiring Diagram ........................................................................\
............................................................G-2
Logic PC Board (L6242-1) Schematic ........................................................................\
.........................G-3
Logic PC Board (L6242-2 & above) Schematic ........................................................................\
...........G-4
Power PC Board (L6252-1) Schematic ........................................................................\
........................G-5
Power PC Board (L6252-2 & above) Schematic........................................................................\
..........G-6
Voltage PC Board Schematic ........................................................................\
......................................G-7
Control Circuit Schematic ........................................................................\
............................................G-8
Procedure Board Schematic ........................................................................\
........................................G-9
Option & Timer Board Schematics........................................................................\
.............................G-10
Meter PC Board Schematic & Layout ........................................................................\
........................G-11
Miscellaneous PC Board Layouts ........................................................................\
..............................G-12
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